Silencer



I June 30, 1931.

K. J. REYNOLDS 1,812,413

SILENCER Filed Jan. 24', 1929 2 Sheets-Sheet 1 MINVENTOR. BY I M ATTORNEYS.

June 30, 1931. J REYNOLDS I 1,812,413

SILENCER,

Filed Jan. 24,'l929 2 Sheets-Sheet 2 Fly. 4.

"u u u v u INVENTOR.

1 BY W3 A TTORNEY S.

Patented June 30, 1931 UNITED STATES PATENT OFFICE KENNETH J. REYNOLDS, OF EAST HARTFORD, CONNECTICUT, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO THE MAXIM SILENCER COMPANY, OF HARTFORD, CONNECTICUT, A.

CORPORATION OF CONNECTICUT SILENCER Application filed January 24, 1929. Serial No. 334,832.

This invention relates to improvements in the construction of silencers with special reference to that type of silencer described in application for U. S. Letters Patent Serial No. 104,458 by Hiram Percy Maxim and Roland B. Iv ourne, and in application Serial No. 201,951 by IIiram Percy Maxim and Roland B. Bourne.

In the above referred to applications, use is made of a plurality of inter-nested, spirally wound, superposed sheets to form a casing comprising a plurality of spiral passageways extending from the interior of said casing to the exterior thereof. In order to hold the several sheets comprising the casing in proper relation one with another whereby the proper depth of passageways may be secured and maintained, some means for spacing and holding said sheets must be used.

In order to greatly simplify the construction and assembly of such a casing and thereby reduce the manufacturing cost thereof and at the same time to provide for the rapid and easy cleaning of the passageways should they become fouled as with carbon or other deposits accumulated during the normal operation of the silencer, I make use of radially disposed rods which not only act as spacers for the sheets but, at the same time, serve to hold the several sheets which make up the scroll-like casing rigidly in place. Further more, certain modifications make it possible to use the spacer-tie rods for holding the scroll-like casing against a header or for 10- eating the scroll within another and exteriorly disposed shell or casing. Indeed, several sets of concentric scrolls may be secured together by providing sufficiently long tiespacer rods to extend the required distance.

To further explain my invention, reference is now made to the drawings, in which:

Fig. 1 is a longitudinal cross-sectional view of a silencer embodying my invention;

Fig. 2 is a section thereof;

Fig. 3 is a detail of one of the sheets;

Fig. 1 is a development of one of the sheets prior to winding into spiral form;

Fig. 5 is a perspective view of the assembly of sheets and tie rods; and

Fig. 6 is a detail of a sheet spacing fixture used in assembling the sheets and tie rods.

Fig. 1 shows a silencing unit constructed in its acoustic principles similarly to the devices shown in the patent applications above referred to. The silencer is contained in a casing 10, preferably cylindrical, to which are attached headers 11 and 12 having suitable connecting means formed thereon by means of which the device may be secured in the inlet or exhaust piping system of the noise-producing apparatus which it is desired to silence. "Within this casing are arranged a plurality of spirally arranged internested metal sheets 13 spaced radially apart through their lengths so as to provide a series of spiral passageways 14, each extending from a central chamber 15 to an annular chamber 16 between the casing 10 and the cylindrical structure formed by the sheet. As explained in the prior applications referred to, high frequency sound Waves are attenuated in passage through these passageways to an unobjectionable intensity, while the total area presented by all the passages in parallel offers no serious resistance to the passage of gas or air. At one end, the passageways between the sheets are closed by the header 11; while at the other, they are closed by a plate 17 preferably formed with a retaining flange 18 which overlaps the outer ends of the coiled sheets. The plate 17 also forms the end of the central chamber 15, and produces a chamber 19 connecting the annular chamber 16 with the opening in header 12. Screws 20 extend through the header 12 and bear on the plate 17 so as to hold the parts in assembled position.

One aspect of the present invention is directed to improving the manner in which the sheets 13 are secured together, and to a method by which they can be economically and accurately assembled. To this end, the sheets 13 are (as best indicated in Fig. 4) provided on opposite edges with a series of notches 21. As shown in this figure, the spacing of these notches is unequal, to compensate for the varying lengths of are bounded by the same angle in the inner and outer portions of the spirally coiled sheets. The notches are preferably, although not necessarily, formed as shown in Fig. 3, with their mouths or openings somewhat narrowed. Small rods 22, of'a diameter sufficient to just snap through the restricted mouths of the notches, are then placed in each of the aligned series of notches and are soldered or welded in place. In order to hold the plates firmly together during the placing and the welding Y of the rods, it is preferable to employ a series of spacing jigs 23 as shown in Fig. 6, having notches 24 into which the edges of the sheets fit. As many of these jigs are used as may be necessary to hold the plates firmly during the assembling and welding operations.

The rods 22 project beyond the sheets and, as shown in Figs. 1 and 2, bear against the inside of the casing 10 to keep the assemblage of coiled sheets a proper distance from the interior of the casing. Similar rods 25, attached to the sheets in the same way, are bent over at right angles and are attached to the plate 17 by nuts 26.

\Vhat I claim is:

l. A wave damping device or silencer comprising a casing, and a structure within the casing comprising a plurality of spirally arranged internested sheets spaced apart radially one from another to form a plurality of spiral passageways, the sheets having a plurality of sets ofradially aligned notchesformed in their end edges, and a plurality of radial tie rods each passing through a set of notches and being'secured individually to each sheet as by weldingor soldering, certain of the rods extending beyond the sheets tofurnish support for the structure within the casing and to space it radially therefrom. p

2. A wave damping device or silencer comprising a plurality of spirally arranged internested sheets spaced apart radially one from another to forma plurality of spiral passageways, the sheets having a plurality of sets of radially aligned narrow-mouthed notches formed in their end edges, and a plurality of radial tie rods each snapped into all the forming a plurality of sheets with narrowmouthed edge notches so spaced that the notches of the several sheets will be in radial V In testimony whereof I have afiixedmy signature.

KENNETH J. REYNOLDS.

notches of a set and permanently secured to g each sheet as by welding or soldering.

3. The method of assembling a scroll-like casing of the type described which comprises forming a plurality of sheets with edge notches so spaced that the notches of the several sheets will be in radial alignment when the sheets are coiled spirally and internested each with the others, coiling the sheets spirally and inter-nesting them, temporarily securing the sheets in proper spaced relation by one or more detachable jigs, inserting radial tie rods in the several aligned sets of notches, permanently securing each rod individually to the several sheets, and removing the temporary jigs.

4. The method of assembling a scroll-like casing of the type described which comprises 

